On 26.03.2020 11:00, Jürgen Groß wrote: > On 26.03.20 10:54, Jan Beulich wrote: >> On 26.03.2020 10:45, Juergen Gross wrote: >>> Today the maximum number of event channels for a guest is defaulting >>> to 1023. For large guests with lots of vcpus this is not enough, as >>> e.g. the Linux kernel uses 7 event channels per vcpu, limiting the >>> guest to about 140 vcpus. >> >> I don't think any particular guest OS should "dictate" the default >> here. What if another OS (or even a future version of Linux) requires >> more than 8? And why would the value depend on number of vCPU-s but >> not number and kind of virtual devices? > > It is a rough estimate. And with HVM guests being limited to 128 cpus > anyway, this problem is more relevant for PV guests, limiting the > available options for guest OS's.
How many evtchns would e.g. mini-os require? I.e. wouldn't such stubdoms get a much larger than necessary allowance this way? Jan
